N-(alkylsulfinyl) ethyl-pyrrolidinones and oxazolidinones



United States Patent US. Cl. 260-307 8 Claims ABSTRACT OF THE DISCLOSURENew compounds having the structure wherein R is an alkyl group of 1 to18 carbon atoms, R is H or an alkyl group of from 1 to 6 carbon atoms, Xis -O or -CH and A is an alkylene group of about 2 or 3 carbon atoms.

All these compounds have antimicrobial activity. Those in which Rcontains 1 to 8 carbons are useful as plasticizers, while those where Rcontains 8 to 18 carbons are useful as nonionic surfactants. Thepyrrolidinone derivatives are quite surface active, while theoxazolidinone de rivatives are less surface active, but are foamboosters.

SUMMARY OF THE INVENTION The instant invention comprises new compoundshaving the structure wherein R is an alkyl group of 1 to about 18 carbonatoms, R is H or an alkyl group of from 1 to about 6 carbon atoms, X is--O or CH and A is an alkylene group of 2 or 3 carbon atoms.

These compositions are prepared by the oxidation of the correspondingthioether with an oxidizing agent. The thioethers can be prepared by thefree radical addition of a thiol to the appropriate vinyl or allylcompound, or by the reaction of an N-(2- or 3-haloalkyl-2-pyrrolidinoneor -axazolidinone with a thiol in the presence of an alkali metalhydroxide. Both processes are known to those skilled in the art.

The oxidizing agents that are suitable for making the compounds of thisinvention include peracids, such as persulfuric, perchromic, peracetic,perbenzoic and monoperphthalic acid; aqueous hydrogen peroxide; anddilute permanganates, such as potassium permanganate and sodiumpermanganate.

The ratio of thioether/oxidizing agent should be from a molar equivalentto about a 10% molar excess of the oxidizer. If more than 10 percentexcess of the oxidizer is used, some of the thioether is oxidized to thesulfone.

The reaction should be carried out from about 0 to 100 C., andpreferably from about 30 to 60 C. a It is generally desirable to have aninert diluent present to act as a heat sink. Materials such as dioxane,the lower aliphatic ketones and the lower aliphatic alcohols aresuitable.

The compounds of the invention have antimicrobial activity. Those inwhich R contains 1 to 8 carbons, and preferably 1 to 4 carbons, areuseful as plasticizers for synthetic resins, such as polyvinyl alcohol,ethyl cellulose, and the like, while those where R contains 8 to 18carbons are useful as nonionic surfactants. The pyrrolidinonederivatives are quite surface active, while the oxazolidinonederivatives are less surface active, but are foam boosters.

SPECIFIC EMBODIMENTS The following are specific examples of the methodof preparation and use of the new compounds disclosed herein.

Examples 1 to 6 In a typical procedure for preparing the sulfoxides,onehalf mole of the thioether in 200 ml. of methanol is heated to -55and one-half mole of 30% aqueous hydrogen peroxide is added during abouta two-hour period. The mixture is stirred an additional hour and thesolvent removed at reduced pressure. The products are white solids quitesoluble in alcohol. Typical compounds so prepared are listed in Table I.

TABLE I Example 7.--Preparation of 3-(3-ethylsulfinyl)propyl-S-methyl-Z-oxazolidinone 8.1 g. (0.043 mole) of3-(3-ethylthio)propyl-S-methyl- 2-oxazolidinone in 50 ml. of methanolwas oxidized as in the above examples with 4.9 g. of 30% aqueoushydrogen peroxide. The resulting product was a viscous orange liquidweighing 8.3 g.

Other compounds, such as3-[(3-pentylsu1finyl)-propyl]-5-hexyl-2-oxazolidinone; 1-[ (2octadecy1-sulfinyl)- ethyl]-4-propyl-2-pyrrolidinone; 1-[(2-t-dodecylsulfinyl)- ethyl]-2-pyrrolidinone and1-[(2-t-octylsulfinyl)-propyl]- Z-pyrrolidinone can be made by oxidizingtheir thioethers in a similar way.

Example 8 The product of Example 7 was used as a plasticizer forpolyvinyl alcohol. 5 g. of the PVA was dissolved in 50 g. of H 0. Elevengrams of this stock solution and 0.25 g. of the above sulfoxide weremixed to give a clear solution. 10 ml. Were cast on a glass plate. Afterthe water evaporated, a tough film remained which retained itsflexibility on standing. An identical batch was also cast without theplasticizer. Upon standing for the same length of time, it became quitebrittle.

Compounds such as 1-[(Z-pentylsulfinyl)-ethyl]-2-pyrrolidinone, 3-(3-heptylsulfinyl -propyl] -4-ethyl-2-oxazolidinone and 1- [(2butylsulfinyl)-ethy1]-2-pyrrolidinone are similar in their effects.

Various of the compounds of this invention were tested as antimicrobialagents. The chemicals tested were diluted in a suitable solvent. Theywere then diluted to the desired concentration in warm melted agar,poured into Petri dishes, and the agar allowed to solidify.

Droplets of the test organism were applied to the sterile agar, and theplates incubated.

The results are given in Table II. The recorded concentrations are thelowest concentrations that prevented growth of the organisms.

TABLE II Microbiological activity of R-SO-CHzCHzN X In vitromicrobiological test Compound P.p.m. to give inhibition S. Can Myco Ath.Bart. P Asp. Rhiz.

R X our. alb. phlei. foot suht. pull. terr. 'mg n-Om CH; 500 500 500 500500 500 500 n-Cn CH; 100 100 500 100 500 500 500 500 n-C 0 500 500 500500 500 500 500 50 n-C12 o 500 500 500 100 100 100 50 Various of thecompounds of this invention were tested We claim: for their surfaceactivity. 1. A compound having the structure Surface tension wasdetermined on 0.1% aqueous solutions with a surface tensiorneter.Interfacial tension Was g I the surface tension between a Nujol mineraloil and a R.SAN x 0.19% aqueous solution. Foam height was determinedwith a Ross-Miles apparatus, while wetting time was determined on aDraves apparatus. These tests are all well known in the art.

The results are recorded on Table III:

TABLE III Surface activity of RSOCH2CI-I2N X wherein R is an alkyl groupof 1 to about 18 carbon atoms, R is H or an alkyl group of from 1 to 6carbon atoms, X is -O or -CH;, and A is an alkylene group of 2 or 3carbon atoms.

2. The compound of claim 1 wherein R is an alkyl group of 10 to 14carbon atoms and R is H.

3. The compound of claim 2 wherein X is CH 4. The compound of claim 1wherein R is an alkyl group of 1 to 4 carbon atoms.

5. The compound of claim 2 wherein X is O.

6. The compound of claim 4 wherein X is O.

7. The compound of claim 2 wherein A is ethylene.

8. The compound of claim 4 wherein A contains 3 carbon atoms and R is 1.

References Cited UNITED STATES PATENTS 3,438,992 4/1969 Shen et a1.260--294.8

ALEX MAZEL, Primary Examiner R. V. RUSH, Assistant Examiner US. Cl. X.R.

